#include<iostream>
#include<set>
using namespace std;

void printSet(const set<int>& s){
	for(set<int>::const_iterator it=s.begin(); it!=s.end(); it++){
		cout<<*it<<" ";
	}
	cout<<endl;
}

int main(){

	set<int> s1;
	cout<<"s1: ";
	printSet(s1);

	set<int> s2_1={9,8,7,6,5};
	cout<<"s2_1: ";
	printSet(s2_1);


	set<int> s2_2({9,8,7,7,6,5});
	cout<<"s2_2: ";
	printSet(s2_2);

	set<int> s3(s2_1.begin(),s2_1.end());
	cout<<"s3: ";
	printSet(s3);

	set<int> s4(s2_1);
	cout<<"s4: ";
	printSet(s4);


	return 0;
}
